If a change does not affect the food's chemical composition, we call it a physical change.

如果一种变化不影响食物的化学成分，那我们便称之为物理变化。

The chemical composition of rainfall changes slightly as raid clouds move.

当雨云移动时，降雨的化学成分略有变化。

The chemical composition of rainfall changes slightly as rain clouds move.

降雨的化学成分随着雨云的移动而发生轻微变化。

Scientists had information about the shape of the domes but not about their chemical composition and origins.

科学家们掌握了关于圆顶形状的信息，但不清楚它们的化学成分和起源相关的信息。

We know they smear a liquid on the tube, but we don't know where they secrete it from or what its chemical composition is.

我们知道它们在管上涂抹了一种液体，但我们不知道它们从哪里分泌出这种液体，也不知道它的化学成分是什么。

Ir is found in high concentrations in some meteorites, in which the solar system's original chemical composition is preserved.

人们发现，在一些保存着太阳系原始化学成分的陨石中，铱元素的含量很高。

Samples recovered from the expedition revealed important differences in chemical composition and fossil distribution among the sediment layers.

探险队采集的样品揭示了沉积物层之间化学成分及化石分布上的重大差异。

When you analyze this light, you can figure out their distance from the Earth, and identify what they are made of, determine their chemical composition.

当你分析这些光的时候，你可以计算出它们与地球的距离，并确定它们由什么构成，查明它们的化学成分。

Each pattern stands for a distinct chemical element, and so different sets or patterns of spectral lines mean that the star has a different chemical composition.

每一种样式代表一种不同的化学元素，所以光谱线的不同集合或模式意味着这颗恒星有不同的化学成分。

The answer to this riddle lies in the metabolic activity of early photosynthetic life-forms that slowly but surely transformed the chemical composition of Earth's atmosphere.

这个谜题的答案在于早期光合生命形式的新陈代谢活动，这种活动缓慢但一定改变了地球大气的化学成分。

The Saussurea involucrata chemical composition was: alkaloid, flavanone, sterol, volatile oil, 16 kind of amino acids, Saussurea involucrata lactone and so on.

雪莲化学成分为：生物碱、黄酮、甾醇、挥发油、16种氨基酸、雪莲内酯等。

This is a chemical composition.

这是化学合成物。

He's doing research into the chemical composition.

他正在研究植物的化学成分。

Long ago, people did not investigate the chemical composition of stones.

很久以前，人们对宝石的化学成分没有研究。

The results actually compared pretty well to the earlier estimate based on chemical composition.

这个结果相比早先根据化学成分计算出来的确实相当不错。

The chemical composition of water remains constant whether it is in solid, liquid or gaseous state.

无论处于固态、液态或气态，水的化学成份都保持不变。

The reflected light is then analyzed in real time(10) to determine the object's chemical composition.

反射光线立刻被机器人分析并说出物品的化学成分。

Heterogeneous bridging groups can raise the glass temperature according to their chemical composition.

不同类桥联基团根据它们的化学组成能提高玻璃化温度。

Chemical Composition More than 180 compounds have been identified in propolis, and many are biologically active.

蜂胶中含有超过180种化学成分，大多数是具有生物活性的成分。

Some specimens, because of their chemical composition should not be washed, also those of the clays or crumbly type.

有些标本，是因为其化学成分不应该洗，还那些粘土或易碎的类型。

The next step is to look at the chemical composition of these planets, their cloud structures and their thermal properties.

下一步是要了解这些行星化学成分，它们的云层结构和热性能。

Technicians can date paint from its chemical composition, for example, or X-ray a canvas to reveal what lies below the surface.

例如，技术人员可以通过其化学成分分析其创作日期，或者对一幅画做X光透视，揭示其表面下有什么。

Ascertaining that a star has exactly the sun's age is impossible, he says, and many unrelated stars share its chemical composition.

他继续补充道，找到一个和太阳有相同年龄的恒星根本没有可能，而且很多和太阳没有关系的恒星也有着与其相同的化学构成。

The random structures formed by packed bubbles, as seen in figure 1, are largely independent of bubble size and chemical composition.

图1中所示的塞满了的气泡形成的随机性结构很大程度上与气泡大小和化学成分是不相关的。

To find out why, researchers used sophisticated X-ray analyses to determine the exact chemical composition of the paint as it browns.

为找出原因，研究人员用精密X射线分析仪测定了变成褐色颜料的精确化学成分。

It measured temperature, pressure, chemical composition, cloud characteristics, sunlight and energy internal to the planet, and lightning.

它测量温度，压力，化学成分，云的特点，阳光和行星内部的能量，以及闪电。

The reserve tanks at a reactor contain the same grade of water in terms of purity and chemical composition that are normally used in the core.

反应堆的储备箱里储备了与反应堆内同等纯度和化学构成的水。